Micrometer calipers



Nov. 17,1925. 1,561,630

R. A. WILSON MICROMETER cALIPERs Filed Nov. 14. 1924 Invenhr.

a7 Roberr 0. Wilson Anya.

rassed '17, 19 25.

. UNITEDFSTATES;

c 1561 630 PATENT mcenonnn'r a'winson, or warm, mssaonusm-rs.

monomim. camm accompanying rawmg, is a specification, like characters on the rawing representing like parts.

This invention relates to micrometer calipers and has for its general object to pro-' vide an improveddevice of this type by which the measurement of any piece of work can be facilitated and'can be accurately made J The type of micrometercahper which 1s now commonly used comprises a ,yoke-.

shaped frame having two jaw members supb means of a micrometer screw. In using this type of caliper to measure the diameter of any piece of work itis necessary first to backpfi the movable jaw by the micrometer screw so asto open the jaws sufiiciently to receive the work between them and then to screw up the screw-actuated jaw by -means ofthe micrometer screw until the two aws en age opposite-sides of'the work.

accuracy ofthe measurementwhich ismade with-this type of instrument .dends. to a considerable extent upon the elicac'y of thetouch of the person us ng the instrument and two persons using the same inst ument will not always arrive at the same -esults simply because one person has a more delicate touch than the other. It :is one of the objects of my present invention to provide a novel construction by actor ofthe touch of the operator.

Another object of the invention .is to prourement can be more rapidly made than with the ordinary type now in use. c

other objects of the inventlon are to improve micrometer calipers in various re-- rted in-the arms thereof, one of which is 4 edand the other of which is adjustable v purpose of measuring .--cate whether the work varies any L predetermined measurement. 'WhlGh the-accuracy of the measurement which is made-is not efi'ected bythe char-5 Vide a micrometer caliper by which a meas-- a knife edge Application .flled November. 1924. Serial Io. 149,859.

. Fig. 4 is a section on the line 4-4, Fig. 1.

The yoke or frame of the calipers is shown at .1 and it is formed with the two arms '2 a1id 3 which support the two jawmembers 4 and 5 between which the work 6 lsmeasured. .The jaw member 5 is of the usual ad ustable type and may be moved to ward an from. the jhws 4 by means of the usual micrometer screw,'the latter comprismg the rotatable handle 7 by the turning of w rob the jaw 5 is advanced or retracted. This rotatable handle is in the form of a sleeve which slides over the stem 8 carrying the scale 9 and said handle is rov1ded 'w1th the peripheral scale 10 a as usual in mic'rometer calipers.

For convenience I will hereinafter refer to the jaw member 5 as the'screw-actuated aw member. a

In'accordance with my present invention the tfiaw member 4 is mounted in the arm 2 at it can have a limited movement to ward and from the jaw member 5.and' a scale, preferably in -the form of a dial, is associated with the jaw member 4 for the or indicating-the extent of its movement. 1

In using the device to test a piece'of work to see if it varies at all from a predetermined measurement, the micrometer screw will be set at exactly the required measurement. The device is then "operated by manually withdrawing the jaw4 so as to open the aws sufiiciently to permit the work to be inserted and then releasing said jaw to (permit it to move it against the work un or spring pressure. The gauge or dial connected with the movable jaw will indifrom the The jaw 4 is shown as having a stem 11 which is .slidably mounted in the arm 2.

This stem is connected to a lever -12pivoted of said lever a recess 15 formed in the stem 11. This glves bearing between the lever and.

to 1 the arm 2 at 13, the end '14 having a dovertail shape and enterin the stem. y f The lever 12 is acted on. by a suitable spring 16 which tends to move the jaw -1 backwardly. This lever 12 is received in a recessor chamberv 17 formed in the frame. Situated within said chamber is an elbow lever 18 which-is pivoted at 19. Said elbow lever has a short arm 20 which engag'esthe its lower end of the arm 12 and ithas a long arm 21-which is formed at its end with the rack teeth 22 that engage a pinion 23 on a stud 24. The stud 24 has fast thereto a graduated dial 25 which operates ina circularopening 26 formed in the side face of the frame so that the dial is exposed to view.

The frame is made with or extension 27 to accommodate the dial. This dial is provided with suitable graduations 28. 4 I

29 indicates a push pin'which is slidably mounted in the frame and is adapted to engage the lever 18, said pushpm having a finger piece 30 situated outside the; frame that can be easily manipulated by the finger 6r thumb of the operator. v

32 indicates a leaf spring whlch is secured at one end to the frame as shown at 33 and at the-other end bears against the lever 18,

said springtending to raise the lever. This spring'32acts in opposition to the'sprlng 16 and it is normally of greater power than the spring 16'so that the resultant tendency of the two springs is to move the aw 4 forwardly toward the jaw 5. When, however,

the finger piece is depressed as shown in ,Fig. 2 the lever 18 will be correspondingly depressedthus moving the short arm 20 of said lever toward the right and allowlngthe spring .16 to act' through the lever 12 to retract the jaw 4.

In order to'illu'strate how the device 1s used we will assume that the piece of work 6 to be tested or measured is supposed to be inch in diameter- 111: P o micrometer screw should be locked .in its set -ure the work the operator Wlll first set the micrometer screw to indicate the .25 inch as shown. He will then depress the-finger piece 30 thereby retracting. the jaw 4 as shown in Fig; 2 and insert. the work 6 betweenthe jaws. The finger piece is then released and the jaw A" will be moved forwardly into contact with the work as shown in Fig. 1 under the influence of the spring 32. The dial 25 will indicate whether the work 6 varies at all in diameter from the desired measurement. The graduations. 28 on this dial may be any denominationhut preferably will indicate-thousandths of an inch and these graduations co-operate with a fixed indication mark 34 which is carried on the frame 1. If the work 6 is exactly .25 inch in diameter then when the j aw A is brought into the position shown in Fig. 1 in ,contact with-the work thezero indication on the dial 25 will coincide with the indication mark 34, this indicating the zero position of the'ja'w 4. If, however, the work 6 has a eater diameter than the .25 inch then 0 jaw twill come up against the workbefore the'zero point ofthe am registers with ;on the dial will indicate the amount which the work 6'is' larger than .25 inch.

the fixed indication point 34 and they reading We willsuppose' that when such a meas the enlargement,

measurement is made, the zero indication mark on the dial registers with the indication mark 34 thus showing that-the work has the correct measurement, During .the

making of these measurements the micrometer screw is not disturbed-but remains set.

extension 27 which scale c'o-operateswith'a pointer36 that is fast on the dial 25, said pointer having a pointed or indicating end 37 that plays over the scale 35;. This scale 35 will preferably he graduated to indicate thous'andths of an inch. The advanta e of -having the scale on the edge is that it acilitates using the device for either dial .or the scale 35 will be visible in any position in. which the implement is used and the reading can be made either from the dial 25 or from the scale 35. Y

Where the device is peated measurements of articles of -approximately the same size it is desirable that the position so asjto avoid any possibility that the setting may 'be disturbed during the hanused' for making re-.'

luo

dling of ,the instrument. I have, therefore,- provided means for locking the jaw 5 in any position in which it may be set. This lock ingmeans is in the form of a locking jaw 38 adapted to frictionally engage the aw 5.

' This jaw 38 operates in an opening 39 formed in the arm 3 and it is provided with a laterally-extending stem 410 which extends through the side of the jaw and has a clamp; ing nut 41 screw-threaded thereto. clamping nut is loosened while the micrometer is being adjusted andafter has been set' to the required reading then the clamping nut 41 is tightened thereby clamping the This ' jaw 5 in its adjus't'edposition. When the jaw-is thus clamped the device maybe freely handled ithoutdanger that the reading of the micrometer will be disturbed. j

The lever 12 is herein shown as adjustable 'as'.to its length, the purpose of this being to provide-means whereby the length of the lever mi be adjusted ifnecessary to ensure an accurate measurement. The lever is accidentally np set or 'shownas having an accurate measurement...

Thelever is shown as having an extension 42 which is adjustably secured tothe main body 43, said extension having a foot piece 44 that engages an arm 2Dof the elbow lever 18. I claim: 4 1. In micrometer calipers, the combination with a yoke-shaped frame having two arms rigid with respect to each other, of a jaw mounted in one'arm thereof, a micrometer 1 screw fol-operating said jaw,a second jaw slidabl mountedin the other arm, a lever pivoted in said other arm and engaging said second jaw, a spring acting on said lever and tending to move said second jaw away from the first jaw, an elbow lever pivotallg mounted in the frame, one arm of whic named lever-ya s'pri acting on said elbow lever and ten g tirough said levers to. move the secondjaw toward the first-named jaw, and a pushpin carried by the frame and bywhich the elbow lever may be moved in opposition to its spring. i

2. Inv 'crometer calipers, the combination with a yoke-shaped frame, of a jaw mounted in one arm thereof, a micrometer screw for operating said jaw, a second jaw slidably mounted in the other arm of the frame, a lever pivoted to the frame and connected to said second jaw, an elbow lever, said lever the frameand having its long arm extending across the bridge portion of said frame and the short. arm engaging the first-named lever, a push pin located inthe bridge portion ofthe frame for actuating the elbow lever, and sprin acting against said levers whereby when t e push pin is depressed the slidable jaw is moved away from the other jaw and when said push p n is released the slidable jaw is moved toward the other jaw. '3. In micrometer calipers, the combination with a yoke-shaped frame, of a jaw mounted in one arm thereof, a micrometer screw for operatigig said jaw, a second jaw slidably mounted in the other arm of the frame, a graduated rotary dial carried in the frame, a system of spring-actuated levers operative- 1y connecting the second jaw to said dial and tending normally to move said jaw toward the screw-actuated jaw, said dial indicating I the position of thesecond jaw and manuallyoperated means acting on said levers to retract said second jaw. j 4; In micrometer calipers, the combination with a yoke shaped frame, of an adjustable elbow lever operatively engages the firsteter screw for adjusting said jaw, a second jaw slidingly carried by the other arm of the frame, a lever'pivoted to the frame and operatively engaging'said second jaw, an elbow lever pivoted to the frame, one arm of which elbow lever operatively engages said first-named lover, a graduated dial operatively'connected to the other arm of sald elbow lever, a spring acting on said elbow lever tending to move the second jaw toward the adjustable jaw, and a push pin carried by the frame and by which the elbow lever may be moved in opposition to,t-he spring thereby to retract said second jaw.

5. In micrometer calipers, the combination with a yoke-shaped frame, of an adjustable jaw carried by one arm thereof, a micr0meter screw for adjusting said jaw, a second jaw slidinglycarried by the other arm of the frame, a lever pivoted to the frame and o eratively engaging said 'second jaw, an

e ow lever pivoted to the frame, one arm having a longand a short arm pivoted to P 7 '5 jaw carried by one arm thereof, a microm-' of which elbow lever operatively engages said first-named lever and the other arm of which is provided with rack teeth, a spring acting on said elbow lever and tending to move the second jaw toward the adjustable jaw, a pivotally mounted graduated dial, a

inion rigid therewith meshing with said rack. teeth, and a pushpin carried by the frame and by which the elbow lever may be moved in opposition to the spring acting thereagainst. l

6. In micrometer calipers, the combination with a yoke-shaped frame, of a jaw mounted in one arm thereof, a micrometer screw for operating said screw, a second jaw slidably mounted in the other arm of the frame, a spring-actuated lever connected to said second jaw and tending normally'to move it away from the first-named jaw, a second spring-actuated levertendmg'to move the first lever in opposition to its spr1ng, a push pin carried by the frame for actuatmgthe. second lever, said frame hzavmg'an:eaten- 10. sion formed with a circular edge, a dial p votally mounted concentrically with said edge and operatively connected to the "second lever, said curved edge being graduated, and

an indicator finger rigid with thedial and co-(iperating with thecurved edge.

In testimony whereof, I have signed my nameto this specificatlon.

ROBERTA. WILSON.

IE1: is hereby bertifiedvtliat-in Letters Patent No; 1,561,630, graritedfNveihbslpli';

51925, upon the application of Robert A. Wilson, of Waltham,'Massachusetts, fdr

an i-fnprovehgent in Micromet'er Calipers, 8,1'1911101 appears in the printed specifica- :tion requiringcorrection as followszPage 3, lines 281and 29; claim 2,- strike but .the words saidl'ever havi'fig along anrL-a shoi'tann a.nd insert thesam'e to follow after the WOld frame 1ine 30, same-claim; and that. th said Letters Patent should be ma with this col-fiction thereinthat the same may conform to the record of the case in the Pgteni Office" 7 v v Y Signed and=-, seglsd'this 5th day 9jf January, .A.- 1). 1926. i i V I Tm A. KINNAN,

- f Actingflommissiqmr of Patents. 

